Vacuum waste systems are generally known in the art for use in transportation vehicles such as aircraft. Vacuum waste systems typically comprise a toilet bowl connected by vacuum piping to a waste tank. A flush valve is disposed between the toilet and the vacuum piping. When the flush valve opens, the contents of the toilet bowl are removed by differential pressure to the waste tank because the air pressure in the line under vacuum is lower than ambient air pressure in a toilet bowl. The flush valve maintains the pressure boundary between ambient air in the toilet bowl and the lower pressure of the piping and the waste tank. In an aircraft, the piping may be placed under vacuum pressure at altitudes under about 16,000 feet by a vacuum source. At altitudes about 16,000 feet and above, the vacuum pressure in the piping may be supplied by the atmospheric pressure differential between the cabin and the exterior of the airplane.
Conventional vacuum waste systems generally consist of a frame structure and a toilet bowl that is mounted in the frame structure. These frame structures can be large and heavy, and thus add unnecessary weight to the aircraft. For example, the frame structures can have the typical height of a toilet, with the toilet bowl assembly being mounted in the frame structure. This additional frame structure needed to support the toilet bowl at a standard height adds weight to the aircraft, which naturally has a negatively impact on fuel efficiency that can add up over many flights and result in significant additional yearly fuel costs to the airline, especially for a fleet of aircraft having such conventional vacuum waste systems. Furthermore, conventional waste systems can be configured to allow the toilet bowls to be removed without a tool, thus making them more prone to tampering.
A need therefore exists for a more effective and efficient vacuum waste system.